In the 1930s, Van Cleef & Arpels was commissioned by a Maharajah to create an aquarium for his pet tree frog. “La Maison d’Hortense” was outfitted with a tiny gold ladder for the frog to ascend or descend, according to the weather. The aquarium was later transformed into its present state, a birdcage housing two carved emerald lovebirds. Estimated at $100,000-150,000.

This ethereal creature was carved from sapphire in the mid-19th century and once owned by Prince Youssoupov, best known as “the man who killed Rasputin,” an act that helped bring down Imperial Russia. It’s estimated to sell for $300,000-500,000.

Scent bottle carved from chalcedony, by Boucheron (Christie's Images)

This charming perfume bottle, c. 1895, takes the form of a cat, carved from black chalcedony with emerald eyes, a collar made of diamonds and a gold bell. One of the treasures from Christie’s cancelled sale of April 2008, this piece has dropped from its 2008 estimate of $80,000-120,000 to a current estimate of $50,000-70,000.